Reputation: 3
Find the percentage of departments that have a manager. Round the result to 2 decimal places.
I am able to find the result of how many departments has manager, but how will i find its percentage?
SELECT department_name
from hr_departments
where manager_id IS NOT NULL;
Upvotes: 0
Views: 89
Reputation: 792
-- % that have managers = (# that have managers / total # of departments) * 100
SELECT ROUND(((SELECT COUNT(department_name)
FROM hr_departments
WHERE manager_id IS NOT NULL) /
(SELECT COUNT(department_name)
FROM hr_departments) * 100), 2)
FROM hr_departments
Upvotes: 0
Reputation: 168361
Since this appears to be a homework question, you want to use an aggregation function to COUNT
the number of departments where the manager_id IS NOT NULL
and compare that to the COUNT
of the total number of rows in the table; then to get the value as a percentage multiply the value by 100 and then ROUND
to 2 decimal places.
Upvotes: 1